Re: [Haskell-beginners] Enum for natural numbers

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Datum: Mon, 21 Dec 2009 19:40:23 +0100 Von: jean verdier An: kane96@gmx.de CC: beginners@haskell.org Betreff: Re: [Haskell-beginners] Enum for natural numbers

your type is data Nat = S Nat | Z and not data Nat = 1 + Nat | 0

Do I have to use something like fromEnum (S Z)? Or or the iteration wrong?

On Mon, 2009-12-21 at 18:27 +0100, kane96@gmx.de wrote:

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Datum: Mon, 21 Dec 2009 15:06:38 +0100 Von: Daniel Fischer An: beginners@haskell.org CC: kane96@gmx.de Betreff: Re: [Haskell-beginners] Enum for natural numbers

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Am Montag 21 Dezember 2009 15:02:16 schrieb kane96@gmx.de:

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In another task I should create an infinite list: allNats :: [Nat] I would have done it in a recursion but there issn't a parameter to call allNats with

Prelude> :t iterate iterate :: (a -> a) -> a -> [a]

this works: allNats = (iterate (1+) 1) but it doesn't match my declaration: allNats :: [Nat]

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